Linked List Pairwise Rotation | Dataford Interview Questions

How would you pairwise rotate or swap the elements in a linked list?

Implement pairwise_swap(head) to swap adjacent nodes by changing links, not node values. The input is a singly linked list, and the output is its new head. For grading, linked lists are represented as arrays of values before and after serialization.

Constraints

0 <= number of nodes <= 1000
Node values are integers
The list is singly linked
The algorithm must not create replacement nodes for the input elements
The relative order within each adjacent pair is reversed

Function Signature

def pairwise_swap(head):

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Problem

How would you pairwise rotate or swap the elements in a linked list?

Constraints

0 <= number of nodes <= 1000
Node values are integers
The list is singly linked
The algorithm must not create replacement nodes for the input elements
The relative order within each adjacent pair is reversed

Function Signature

def pairwise_swap(head):

Your question is Linked List Pairwise Rotation. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.